common tool for intelligent scheduling / critical chain ... · common tool for intelligent...

Common Tool for

Intelligent Scheduling /

Critical Chain Project Management

for US Navy & Contractor Shipyards

Rob Richards, Ph.D.

April 20, 2016

Planning, Production Processes &

Facilities Panel (PPP&F) Meeting

19-20 April, 2016

Portland, Oregon

Distribution. Approved for Public Release: Distribution Unlimited

Enhancements to Traditional Project

Management

Project Management

Critical Chain

Intelligent Scheduling

www.StottlerHenke.com

Benefits

Current Benefits

Execution driven by

global priorities

Greater throughput with same resources

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US Navy Shipyards & Contractors

Utilize Many Scheduling / Project

Management Tools

Primavera P6

Artemis

PS8 (by Sciforma)

Open Plan (by Deltek)

Microsoft Project

PSS

Databases / Non-traditional PM tools: e.g. SQL

Server

Navy & Contractor Tools

Project Management: Primavera P6

ArtemisPSS

Open PlanMS Project

PS8Aurora

Critical Chain:PS8

Aurora

Intelligent Scheduling:Open Plan

Aurora

Aurora Functionality

Project Management

Critical Chain


Aurora

Interfaces: Aurora can interface will

all others

Build in current tool: Benefit from

Intelligent Scheduling &/or Critical

Chain

PSS Case Study (1)

• PSS – Solution used by US Navy

– Single project only

• Developed Aurora import capability

• Successfully scheduled sample PSS

provided by the Navy

– Informed that PSS project models have

not been successfully scheduled in other

tools

PSS Case Study (2)

• Multi-project: Aurora successfully performs

multi-project scheduling from multiple PSS

models

– Over 70,000 total tasks

– Capability not currently available to the

Navy

Projects Completed by

• Synchronized effort of multiple resources

• Goal of Intelligent Scheduling: optimize the synchronization of resources and other constraints to minimize the duration of the project

Intelligent Scheduling: Expert

Knowledge & Experience Needed

• Mathematics is not enough (Problem is NP-Complete, takes exponential time for optimal solution)

• Encoding expert knowledge & experience in software can make this knowledge available to others

– Found domain specific heuristics many times beneficial in other domains.

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Aurora Summary

World’s most intelligent scheduling engine and

standard project management features

• Multiple-pass intelligent resource-constrained

scheduling

• Mixed-mode scheduling providing both forward

and backward scheduling, available on a task-by-

task basis

• Schedule Rationale – Aurora includes the

rationale for each task on why it was schedule

where it was schedule

• Designed for customization

• Designed for integration

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Aurora Customers (1)

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Aurora Customers (2)

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Value Proposition: Aurora

The EXACT same project can be completed

significantly faster by using the intelligent

scheduling engine in Aurora, versus ANY

other software available.

• That is, once the resource-loaded project model is

developed, using Aurora will determine a shorter

initial schedule, and then by using Aurora during

the execution of the project Aurora will make more

efficient decisions based on the reality on the

ground so the execution results in a shorter

project duration versus any other software

available.

Why order matters?

A

B

C

E

D

Schedule 1: B before C

A B C ED

Schedule 1: C before B

A BC ED

The example below involves jobs using two resources, purple and white

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Aurora-CCPM Summary

Enterprise-Level Critical Chain Project

Management Software

Multi Project

Provide GLOBAL view of entire project –

prioritize execution to maximize overall project

benefit

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Potential Workflow with P6:

Flowchart for Critical Chain

Build in

Primavera P6

PMs use updated Primavera

P6 model for EVM, etc.

Schedule in

Aurora

Enter status updates

Transfer to Aurora via XER

Transfer results to Primavera P6

PMs use updated Aurora

model for Task Priorities via

Critical Chain

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Aurora Unique

Capabilities & Benefits (1)

Large project support• Supports 100,000+ tasks per project

Integrates with Enterprise Software• Oracle, SAP, proprietary systems

Multiple-pass intelligent resource-constrained

scheduling• Generates shorter project duration & shorter remaining

project durations during execution

Mixed-mode scheduling providing both ASAP & ALAP

scheduling, available on a task-by-task basis.• All other critical chain software only provides ALAP

scheduling

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Aurora Unique


Primavera P6 Integration• Only Critical Chain software that is designed to work with

Primavera P6

Support beyond Finish-to-Start Constraints• Only software that understands and can perform Critical

Chain with S-S, F-F, etc., also supports Leads and Lags.

Schedule Rationale

• Aurora includes the rationale for each task on why it was

schedule where it was scheduled

Designed for Customization

• Can be extended to work with enterprise specific needs

Aurora Unique


Supports More Types of Constraints

• Resource constraints

• Resource Sets – job can be performed by 2 different

specialists or (1 generalist and 1 specialist) or 2 generalists.

• Spatial constraints – e.g.,

– job requires a certain location or type of space;

– two elements should (or should not) be next to each

other

• Ergonomic constraints – individual limitations on work

conditions

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Aurora Unique


Supports More Types of Constraints

• Skills / Certifications in addition to Occupations

– E.g., Mechanic (occupation) with 4 additional skills or

certifications

• Constraints based on status/state

– E.g., no hot work when other conditions in effect

• Shift based constraints

– Task needs to be completed during single shift

– Do not start task unless x% of time left in shift

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Explanation of Why each Task was Scheduled

Where it was

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Schedule Results: Explanation

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Resource Contention: Visual

Viewing resource contentions in Aurora

In this sample schedule, each task has a

resource requirement attached as follows

Resource-constrained

relationship

Note that there is a total amount of only 5

resources. Tasks 2, 4, and 5 are started at

the same time (5 resources used). Task 2

completes, but there are not enough

resources left to start Task 6, so Task 6

must wait until Task 5 is complete.

Task # Resources Needed

2 1

3 2

4 2

5 2

Aurora shows you this resource-constrained relationship with a blue-grey

line between the two Tasks.

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Resource Contention: Task 6

Single Element Display

Overall schedule flow

Gantt Chart View

The Single Element Display in

Aurora helps the user visualize the

relationships between tasks:

•Blue-grey lines denote a resource-constrained

work flow

•Red lines denote temporally-constrained work

flow

Referring to the three diagrams to

the right:

•Task 6 can start any time after Task 2 is

completed (red line in Single Element Display),

but must wait for Task 5 to release resources

(blue-grey line).

•Tasks 3 and 8 must wait for 6 to release

resources before they can start, as shown in

the Gantt Chart View

•Task 7 starts after Task 6 completes (red line in

Single Element Display)

Constraints Add Complexity

• Technical constraints (E.g., F-S, F-F, S-F, lags)

• Resource constraints

– Labor constraints

– Equipment, Tools (e.g., cranes)

• Usage constraints – e.g., tool can only be used for

so many hours continuously &/or during a day.

• Spatial / physical space constraints – e.g.,– job requires a certain location or type of space;

– two elements should (or should not) be next to each other

• Ergonomic constraints – individual limitations on

work conditions

More Complexity:

Shipbuilding & Ship Maintenance

Concurrent & Non-Concurrent

• Complex operations requires concept of

concurrent & non-concurrent tasks

• Adds another layer of complexity

Turnaround Project Network 2,500+

Tasks

Results: 2,500+ Turnaround

• Primavera P6 65 days

– Performed by 3rd party

• Aurora 57 days

• Primavera P6 14% longer than Aurora

• Critical Path is 46 days

– P6 is 19 days longer than CP

– Aurora is 11 days longer than CP

– So % diff over CP is > 73%

Maybe Only for ‘Big’ Problems?

• Let’s look at a toy problem …

• ‘Simple’ problem with only 7 real tasks and 2

milestones.

‘Simple’ Network details• Number superscript of circle is duration in

days

• Number subscript of circle is resources

needed

• There is only 1 type of resource

Critical Path of Network

• Solution when infinite resources available

• Find longest path = 1 + 1 + 5 = 7

• So Critical Path is 7 days

Gantt Chart of Critical Path

• Note: Sat/Sun are not workdays

Set Resource Pool to 5

• Only one type of resource to make the

problem ‘simple’

Gantt Chart Showing the Critical

Path & Histogram

• Note: now some resources are overloaded

• Resource level to solve over allocation

Resource-Leveled in

MS Project = 9 days

3

1 5

4 7

2 6

Resource

Units

Resource

Units

Time Time

Simple Enough, Right?

• Another view of the solution

But there is a better solution …

P6 Model: Resource Leveled = 8

days

Simple?

• Critical Path =

1 + 1 + 5 =7

• 1 resource

5 total units

End of Story… Not quite

• There is an even better solution

• 7 days

• So this ‘simple’ problem could not even be solved

well by the world’s ‘premier’ project management

tools.

• Can you solve this ‘simple’ problem in 7 days?

Tetris

• Shapes similar to resource

profile of individual tasks

• Holes when playing Tetris

represent resource

allocation inefficiencies.

– E.g., black regions in

figure to the right

Primavera Resource Leveling flowchart

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Long-Term Refinery-Related

Upgrade

MS Project 2007 = 1,627 days

Primavera P6 = 1,528 days

Intelligent scheduling

(Aurora) = 1,240 days

300 Task Example: Aerospace

Application

Multiple Resource Types Needed for most tasks

300 Task Example: Network in Aurora

Results: 300 Task Example

• MS Project 2003 145.6 days

• MS Project 2007 145.6 days

• Primavera P6 115 days

– Performed by 3rd party

• Deltek Open Plan 110 days

– Performed by Deltek

• Aurora 102.5 days

Take Aways

• Scheduling engine is critical

• Paying up to 100% penalty due to the scheduling engine

• Changing to an improved scheduling engine may be the greatest potential improvement available to your project

– Just press a different button

• Provide an unfair competitive advantage

Aurora: Intelligent Scheduling /

Critical Chain Project Management

Project Management

Critical Chain


Aurora

Requires resource 1 Requires resource 2 Requires resource 1 and 2

As scheduled:

Critical chain:

Critical Chain – Example 3

Why can’t you search for the best order?

• Ordering options scale as N!

Two tasks that can occur in either order (one at a time)

results in two options

Three tasks that can occur in any order (one at a time)

results in six options

Four tasks that can occur in any order (one at a time)

results in twenty-four options

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Why Intelligent Scheduling?

Resource-loaded scheduling is difficult

• Whole field of Operations Research

Not leveraged in the Project Management

domains that Primavera serves

Usually demand is generated from

knowledgeable users

Not promoted by solution providers

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Tasks,

Resources,

Constraints

Preprocessor

Task

Queue

Schedule

Objects

Task Ordering:

Pick a Task

Select/Assign

Resources Task

& Time Window

Handle

ProblemsProcess Task

Propagate

Constraints

Fix Problems &

Optimize

Schedule

Human

Directives

Criteria &

Instructions

Methods &

KnowledgeGuidance

Problem

Resolution

Knowledge

Knowledge

Editors

Aurora Architecture

Benefits of Sophisticated Underlying

Scheduler

• Results in a better initial schedule

• Execution: Schedule is more flexible and better able to accommodate change.

– Schedule is “self-aware” of what tasks can most easily be moved. I.e., tasks store information about why it was placed (where it is placed).

Scheduling is Fast

• 300 tasks ~ 3-6 seconds

• 2,000 tasks ~ 11 seconds

• 3,000 tasks ~ 15-20 seconds



• High degree of variation - it depends a lot on the

shape of the problem

Results

• Multiple sources reveal the effect of the Scheduling Engine

• For larger projects (>1,000): Aurora has been able to find project durations SIGNIFICANTLY shorter than other software for the same data set.

• Much of the potential improvement offered by modeling resources is being squandered.

• Resource leveled schedules are sub-optimal

Planning & Execution

• Initial Schedule benefits

• Execution benefits even MORE

– If scheduler is inefficient, every delay will be

magnified because re-allocation of resources

will be deficient

Benefits of Sophisticated Underlying

Scheduler: Planning & Execution

• Results in a better initial schedule

• Execution: Schedule is more flexible and better able to accommodate change.

– If scheduler is inefficient, every delay will be magnified because re-allocation of resources will be deficient

– Schedule is “self-aware” of what tasks can most easily be moved. I.e., tasks store information about what placed it where it is placed.

Critical

Resources

• Initial schedule usually has different critical

resources via different schedulers

• Execution mode updates will also usually

have different critical resources

– Picking less than optimal resources if

resource increases are used to make up

slippage.

• Better to find more efficient schedule with

intelligent scheduling, then increase critical

resources if necessary.

Analogy: Chess

• Chess mathematically is similar to resource

loaded scheduling.

– Easy: Create basic rules to play

– Hard: Win against other intelligent players

• Resource Leveling in most software is

analogous to 'Easy' chess solution

• Each move analogous to execution mode

update, challenge continues throughout

game/execution of schedule

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